No 8 Joy Neville's opening try came after just six minutes as she pounced to crash over on the day she won her 50th cap. The swirling wind made the conversion difficult and Niamh Briggs' effort missed the target.

The Americans' first score came from a scrum, which allowed prop Jamie Burke to crash over. Out-half Christy Ringgenberg added the extras for a 7-5 lead.

It was Briggs who brought Ireland back into the game before half-time with a fine try after a good Irish line-out secured possession. Impressive hooker Gillian Bourke's delivery was good, releasing Briggs, who outpaced USA skipper Ashley English to touch down for a 10-7 advantage.

A series of line-outs were rewarded when Ireland scored again, with an excellent surge from Neville producing her second of the day to leave Ireland 15-7 ahead.

Despite the game being tight, the Irish secured the bonus point midway through the half. Scrum-half Tania Rosser reacted quickly to a penalty inside the USA '22' and her pace took her to the try line. Briggs kicked her first conversion of the day and Ireland led 22-7.

USA efforts were rewarded with a try from Vanesha McGee, to leave 10 points between the sides.

Ireland managed to hold out, though, and take what was a vital victory. They meet Kazakhstan on Saturday (kick-off 4.30) in their final pool game before next week's play-offs.